Field of the Invention
The present invention relates to a display device including an interface device capable of effectively transmitting sensing data for external compensation while using an encrypted transmission technology during communication between a display module and a control module externally separated from the display module for slimness of the display module.
Discussion of the Related Art
As the information technology has advanced, the market of display devices as mediums connecting users and information has grown. In line with this, the use of display devices such as liquid crystal displays (LCDs), organic light emitting display devices, electrophoretic displays (EPDs), and plasma display panels (PDPs) has increased.
Representative examples of flat display devices recently highlighted as display devices to display an image, using digital data, include a liquid crystal display (LCD) using liquid crystals, an organic light emitting diode (OLED) display using OLEDs, and the like.
An organic light emitting diode (OLED) display device is a self-luminous device in which an organic light emitting layer emits light through re-combination of electrons and holes. Since the OLED display device exhibits high luminance, and uses a low drive voltage while achieving slimness, the OLED display device is expected to be a next-generation display device.
Such an OLED display device includes a plurality of pixels, each of which includes an OLED constituted by an anode, a cathode, and an organic light emitting layer interposed between the anode and the cathode, and a pixel circuit for independently driving the OLED. The pixel circuit includes a switching thin film transistor (TFT) for supplying a data voltage to a storage capacitor, a drive TFT for controlling drive current in accordance with a drive voltage charged in the storage capacitor, and supplying the controlled drive current to the OLED, and so on. The OLED generates light having a light amount proportional to the amount of the drive current.
In OLED display devices according to the related art, however, non-uniformity of luminance may occur because there may be deviations of driving characteristics (threshold voltage and mobility) of drive TFTs among pixels due to process deviation and with passage of time. In order to solve such a problem, OLED display devices use an external compensation method for sensing driving characteristics of each pixel, and compensating data to be supplied to the pixel, using the sensed value.
OLED display devices are applicable to various products such as portable terminals, TV sets, flexible displays, transparent displays, and so on. Recent advances in OLED display devices are focused on slimness, for application of such OLED display devices to a paper display or a wallpaper display.
For slimness of a display module in an OLED display device, a scheme to externally separate a part of circuit configurations mounted in the display module should be taken into consideration. In this case, an encrypted transmission system is required in order to protect content during communication between the display module and the separated circuit configuration. In particular, when an interface using the encrypted transmission system is used, problems associated with transmission of sensing data required for external compensation of the OLED display device should also be taken into consideration.